Recently, in the vehicle industry, there is a continuous demand for vehicles to exhibit increased durability, stability and fuel economy, and much effort is directed to satisfying the demand.
In particular, many attempts have been made to enhance the properties of rubber, as a material for vehicle tires, especially tire treads, which are in contact with roads. The rubber composition for a vehicle tire contains a conjugated diene-based polymer, such as polybutadiene or butadiene-styrene copolymer.
Thorough research is currently ongoing into the addition of various reinforcing agents to conjugated diene-based rubber compositions to increase the performance of vehicle tires. Specifically, as vehicles are required to exhibit stability, durability and fuel economy, rubber compositions having excellent wet skid resistance and mechanical strength, as well as improved heat build-up, are being developed as material for vehicle tires, especially tire treads, which are in contact with roads.